The inherited disease sickle cell anemia occurs because of an abnormally shaped protein taking the place of one of the chains.
a. alpha
b. beta
c. gamma

B. beta

Explanation:

Sickle cell anemia is a inherited disorder which occur due to mutation of gene responsible for synthesis of hemoglobin protein. Typically the gene which is responsible for synthesis of beta-globin protein which make the beta chains in the hemoglobin is affected by the mutation.  As a result of this the red blood cells acquire a shape of sickle rather than round. Pain, cold, stress, dehydration and illness are the symptoms associated with this disorder.

1.the evidene of the reaction

2.yes

3.yes

the areas around the equator